Safety wire interrupter assembly

ABSTRACT

An improved safety wire interrupter and method of arming munitions wherein a plastic member, such as high or low density polyethylene, is fused onto the safety wire to prevent withdrawal of the safety wire from a safety pin until tension is applied to a lanyard means fixedly connected to the safety wire.

, 3 A EJ ate Sttes ate t 1191 1111 3,828,645

Testerman et al. Aug. 13, 1974 SAFETY WlRE INT ERRUPTER ASSEMBLY [56] References Cited [75] Inventors: Joseph E. Testerman; Louis A. UNITED STATES PATENTS Robertson, both Of Edgewoodt 3,316,841 5/1967 McFann et al 102/76 R Ass g e The United States of America as 3,515,777 HOithflLlS X represented by the Secretary of the Army, Washington [10 Primary Exammer-Samuel W. Engle Attorney, Agent, or Firm--Edward J. Kelly; Herbert [22] F1led: Jan. 9, 1973 Ber] 211 App]. No.: 322,259

Related U.S. Application Data [57] ABSTRACT [63] Continuation of Ser. NO. lll,896, Feb. 2, 1971, An lmproveflsafety mtefwPter and method of abandoned arming mumtions wherem a plastlc member, such as high or low density polyethylene, is fused onto the [52] U.S. Cl. 89/1.5 D, 102/81.6 f ty wire to prevent withdrawal of the safety wire [51] Int. Cl B64d 1/04 m a f ty pin until tension is applied to a lanyard [58] Field of Search 156/275; 102/76, 77, 70, m n fix dly onnected to the safety wire.

102/811 816; 89/15 D 2 Claims, 5 Drawing Figures PAIENIEM 1 3'3" PRIOR ART INVENTORJ' Joseph E. Tester/nan Louis A. Robertson SAFETY WIRE INTERRUPTER ASSEMBLY This is a continuation of application Ser. No. 111,896, filed Feb. 2, 1971, now abandoned.

DEDICATORY CLAUSE The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.

Our invention relates to an improved safety wire interrupter and method of arming munitions. The prior art means and method of arming munitions utilized a safety wire having a steel ball swaged on the wire and the wire fixedly connected to a lanyard means; the safety wire retaining a safety pin to prevent activation of an intervalometer means and arming of the munition until tension was applied to the lanyard means. In the prior art device, the safety wire was inserted in a slot formed in the flanged base of the intervalometer means so that the steel ball swaged on the wire was against the flange surface of the base contacting the munition and the wire extended through the flange to be connected to the lanyard means; the steel ball thus preventing removal of the safety wire from the aforementioned pin until tension was applied to the lanyard means. Upon applying tension to the lanyard means, the steel ball could not be pulled past the flange of the intervalometer base, and the wire would be removed from the steel ball and the safety pin release the pin to activate the intervalometer and arm the munition. However, the problem existed with the prior art means that the steel ball could not always be removed when tension was applied to the lanyard means which resulted in munition misfiring. Therefore, our invention was conceived and reduced to practice to solve the above described prior art problem and to satisfy the long felt need for a safety wire interrupter and method of arming munitions which is effective and reliable.

A principal object of our invention is to provide a safety wire interrupter means and method of arming munitions which is effective and reliable.

Another object of our invention is to provide a safety wire interrupter means and method of arming munitions which is effective and reliable and does not require any munition or mode of activation modification.

Other objects of our invention will be obvious or will appear from the specification hereinafter set forth.

FIG. 1 is a view showing the prior art device having a steel ball swaged on a safety wire interrupter.

FIG. 2 is a view of our improved safety wire interrupter having a plastic member fused on the wire.

FIG. 3 is a view showing our improved safety wire interrupter mounted in an intervalometer base and holding the safety pin in the unarmed position.

FIG. 4 is a view through 44 of FIG. 3.

FIG. 5 is a view showing the utility of our improved safety wire interrupter in cooperation with an intervalometer, munition, and lanyard means.

Our invention, as shown in FIGS. 2 to 5, will now be described in detail as follows.

Any suitable plastic, such as high or low density polyethylene, is used to form member 1 to be removably mounted on wire 2. Member 1 can be designed and molded within the skill of the art to any selected size and configuration to suit any given application. The design of member 1, as shown in FIG. 2, e.g., having an upper portion and a lower reduced portion was selected so that the disk-shaped upper portion of member 1 fits within a recess in the lower surface of flange 3, as shown in FIG. 3, of the intervalometer shown at 4 in FIG. 5; intervalometer 4 being fixedly mounted on munition 5 shown in FIG. 5 and electrically connected to a conventional fuze means within munition 5 in the conventional manners, the munition and intervalometer not being a part of this invention and not being shown in detail. Member 1 is mounted on wire 2 by sliding wire 2 through a hole in the center of member 1, the hole being of such dimensions that the fit of member I on wire 2 is a friction fit, to a predetermined position on wire 2 which will permit member 1 to seat within the recess of flange 3 and wire 2 to extend through a hole in safety pin 6, as shown in FIG. 3. After placing member 1 at the aforementioned position, electrical leads from a direct current power source are connected to wire 2 on each side of member 1, and a sufficient DC voltage is passed to fuse member 1 to wire 2. Wire 2 is then inserted through a hole in safety pin 6 to hold pin 6 under spring tension, by means of spring 7, and in the unarmed position within munition 5, as shown in FIG. 3. After securing pin 6 in the unarmed position by wire 2, wire 2 is inserted in the slot of flange 3 shown at 8 in FIG. 4 to permit member 1 to seat within the recess of flange 3, and intervalometer 4 is fixedly connected to the upper surface 9 of munition 5 by any conventional means, such as screws 10 shown in FIG. 3, to produce the structure shown in FIG. 3. The loops shown at 11 of wire 2 is fixedly connected to lanyard 12, as shown in FIG. 5. When it is desired to activate munition 5, tension is placed on lanyard 12 by any conventional means, such as pulling by hand or ejecting munition 5 from an aircraft with lanyard l2 fixedly connected to the aircraft, which pulls wire 2 from member 1 and out of the hole in pin 6. Upon removal of wire 2 from pin 6, tension induced by spring 7 ejects pin 6 from munition 5 which permits activation of intervalometer 4 and arming munition 5 in the conventional manner; intervalometer 4 being activated by the withdrawal of pin 6 from a slot in the intervalometer shaft means, not shown in the drawing and not being a part of this invention.

It is obvious that other modifications can be made of our invention, and we desire to be limited only be the scope of the appended claims.

We claim:

1. In a munition system having a plurality of components comprising a container means, a payload within the container means, flange means positioned on the top of the upper surface of the container means, said flange containing a recess therein, a firing mechanism to activate the payload, an intervalometer means to arm the firing mechanism, lanyard means, a spring loaded safety pin adapted to activate the intervalometer means upon release of the safety pin means on application of tension to the lanyard means: the improvement in combination with the above components being a safety wire interrupter having a plastic member separably fused thereto through the center of said member, said plastic member having a disk-shaped upper portion and a lower reduced portion, the upper portion of the plastic member seated within a recess in said flange integral with the intervalometer means, said wire interrupter being connected to said lanyard means and holding the safety pin in an unarmed position until tension released for activating said intervalometer means. is applied to said lanyard means; whereby upon ten- 2. The munition of claim 1 wherein the plastic memsioning of said lanyard means said safety wire is sepaher is polyethylene.

rated from said plastic member, and said safety pin is 

1. In a munition system having a plurality of components comprising a container means, a payload within the container means, flange means positioned on the top of the upper surface of the container means, said flange containing a recess therein, a firing mechanism to activate the payload, an intervalometer means to arm the firing mechanism, lanyard means, a spring loaded safety pin adapted to activate the intervalometer means upon release of the safety pin means on application of tension to the lanyard means: the improvement in combination with the above components being a safety wire interrupter having a plastic member separably fused thereto through the center of said member, said plastic member having a disk-shaped upper portion and a lower reduced portion, the upper portion of the plastic member seated within a recess in said flange integral with the intervalometer means, said wire interrupter being connected to said lanyard means and holding the safety pin in an unarmed position until tension is applied to said lanyard means; whereby upon tensioning of said lanyard means said safety wire is separated from said plastic member, and said safety pin is released for activating said intervalometer means.
 2. The munition of claim 1 wherein the plastic member is polyethylene. 